US2237538A - Swedge - Google Patents

Description

April 8, 1941.

J. A. ZUBLIN 2.237.538

SWEDGE Filed Feb. 25, 1939 Patented Apr. 8, 1941 UNITED STATES PATENT OFFICE SWEDGE John A. Zublin, Los Angeles, Calif.

Application February 25, 1939, Serial No. 258,438

4 Claims.

The present invention relates to a swed e or casing roller, being particularly directed to a tool adapted for operation within well casings and liners.

It is an object of this invention to provide an improved swedge for restoring buckled, dented or collapsed casings and liners to their original inside diameters.

A further object of the invention is to provide a swedge having 'a combined rotary and reciprocat-- ing or oscillating motion.

Still another object of the invention is to provide a swedge of sturdy and relatively simple construction, insuring safety in its use anddependability in its performance.

This invention possesses many other advantages and has other objects that will become apparent from a consideration of several embodiments of the invention. Accordingly, forms are shown in the drawing accompanying and forming s a of Figure 1; a

Figure 4 is a side elevation of modified form of roller; and

Figure 5 is a section taken on line 5-5 of Figure 4.

A completely assembled swedge is disclosed in a swedge with a Figure 1, including a supporting-member or shank portion l attachable to the lower end of a string of drill pipe ll through the agency of a tapered,

threaded pin I 2 provided on the upper end of the shank. The lower end of the shank is provided with a swedge roller bearing l3 whose axis 'A--A is inclined with respect to the axis 13-3 of the shank and hole or casing within which the tool is operable. The inclined bearing l3 consists of a cylindrical portion I4 for transmitting radial loads, and a terminal frusto-conical thrust portion l5 designed to carry substantially all of the axial loads and part of the radial loads. These bearing portions can be made integrally with the shank, but since the major portion of the wear occurs on the frusto-conical portion l5, it is preferred to make this part removable and replaceable by threadedly securing it within the cylindrical bearing portion M.

A swedge roller l6, designed for operation upon casings, liners and the like, is rotatably mounted upon the inclined bearing l3, and is provided with an internal cylindrical bearing surface I! and an internal frusto-com'cal bearing surface 18 respectively cooperalble with the cylindrical and frustoconical surfaces on the inclined bearing.' The inside of the cutter is also provided with a groove or raceway I 9 adapted to receive retainer or hearing elements, such as balls 20, which are also contained within an external circumferential groove or raceway 2| provided in the cylindrical portion H of the hearing. The swedge roller I6 is therefore prevented from moving downwardly from the shank and its bearing by the locking action of the balls. Upward movement is restrained and restricted by the cooperation between the frustoconical bearing surfaces l5, l8.

The balls 20 are inserted into the raceways l9, 2! through a longitudinally extending recess 22 in the shank bearing communicating with the bearing raceway 2|. After the swedge roller has been placed in proper position upon the inclined bearing, the balls 20 are inserted into the complementary raceways l9, 2| through the recess 22, after which they are confined within the raceways by a plug or lock 23 held within the recess by means of a screw 24 extending therethrough and threaded into the body of the shank. As a precautionary measure, a safety screw 25 can be threaded into the shank immediately above the lock to insure against its removal. The lower end 26 of the lock is suitably curved to afford continuity of the raceway in the bearing.

The manner of locking the roller to the shank and the general mode of cooperation between the bearing surfaces is fully described and claimed in my Patent No. 2,025,259, patented December 24, 1935, entitled Drill bit, to which attention is invited.

The shank is provided with a passageway 27 for drilling fluid, which flows therethrough into a passage 28 in the inclined bearing pin 15, communicating with a hole or passageway 29 extending through the lower portion of the swedge roller, permitting circulating fluid to remove formation and other particles of matter from the casing, and thereby allow unimpeded operation of the swedge. A supplementary fluid discharge nozzle 30 is also threaded into the shank, and communicates with a passageway 3! opening into the'main shank passageway 21. Fluid issuing from this nozzle will act upon the outer surfaces of the swedge roller and maintain them free from foreign matter.

As disclosed in the drawing, the swedge roller I6 is of generally conoidal shape with a lower portion 32 tapering downwardly toward a theo retical point 32a, and with an upper portion 33 of generally curved shape, preferably forming part of a spherical surface. The spherical surface merges into the tapered surface, preferably at the greatest diameter of the sphere, resulting in a roller having a substantially continuous outer surface, capable of effective operation within a casing.

Referring to Figure l, a casing 34 is disclosed with a buckled or collapsed section 35 therein. The swedge is lowered within the casing to the defective region, and the shank I0 is rotated through the usual drill pipe H and other instrumenta-lities. Due to the angle p at which the bearing is inclined relatively to the axis or center line BB of the shank, the roller 16 is given a wobbling or gyratory motion, which motion is a combination of a rotary movement upon the inclined bearing coupled with a reciprocatory or oscillatory movement of the roller generally transversely of the casing. Suitable weight is applied to the swedge, causing its roller 15 to contact with the defective casing portion 35. As the swedge rolls around the casing and oscillates therein under the influence of rotation of the shank and its inclined bearing, the buckled casing portion will be gradually and smoothly pressed back toward its original shape and size. If the buckling is relatively slight, the upper portion 33 of the tapered roller part and the spherical portion will be effective in forcing the bent casing part back into place. But if the buckling is material, or if undue resistance.

is offered by it, the smaller nose 32 of the roller will first operate upon the casing, its reciprocation or oscillation bending the defective portions laterally outwardly, permitting the rolling action to re-form it smoothly into its original smooth shape. As thi original shape is being restored, the swedge will be lowered further into the casing to provide a progressively larger roller diameter for rolling purposes upon the deformation. When the roller can pass freely through the casing, the bore will have been restored to its initial inside diameter, or whatever lesser diameter is desired.

In a preferred design of the swedge roller, its maximum diameter at right angles to its inclined axis of rotation A--A is no greater than the inside diameter of the casing or liner within which it is to operate. This diameter can be the maximum diameter of the upper spherical portion 33 of the outer roller surface. From the largest roller diameter, the outer roller surface tapers downwardly, as aforementioned. This taper can be such as to provide a terminal frustoconical outer surface 32, although it is to be appreciated that other conoidal shapes can be used, since it is not essential that the tapered surface be part of a right circular cone. The degree of taper is also preferably such that one half of the apex angle q of the cone i greater than the angle of inclination p of the rotational axis A--A of the roller with respect to the casing or shank axis B-B. This design is preferred in order that the tapered surface 32 will be inclined inwardly toward the axis of the hole B-B to permit it to be positioned initially below the uppermost portion of the deformation, and

iii

thereby allow the gyratory motion of the rolle to be effective in pressing and rolling the casin back to its original shape.

The mounting of the roller for rotation abou the inclined axis BB provides a large mechani cal advantage between the shank l0 and th roller l6, making it possible for the roller to ex ert a larger force upon the casing. This me chanical advantage arises from the fact that th transmission ratio between the revolutions of thi shank within the casing and the revolutions o: the roller upon the inclined bearing is mucl greater than one. It has been found that thr inclining of the bearing 30 degrees to the shanl axis will provide a transmission ratio of abou1 6 to 1, depending upon the degree of slip. 01 course, thi ratio and the mechanical advantage could be further increased by pitching the inclined axis more steeply, as, for example, making the angle of inclination 20 degrees.

A slightly modified form of swedge roller is disclosed in Figures 4 and 5. It is not essential that the outer surfaces 32, 33 of the roller It be perfectly smooth, as is disclosed in Figure 1. The roller can be provided with slightly raised longitudinal portions or ribs 36, preferably merging smoothly into shallow longitudinal grooves 31, forming, in efiect, a very shallow and slightly corrugated surface. This type of surface is substantially continuous and is of generally conoidal shape, producing a knuckling or kneading action upon the casings and liners to form them into the desired shapes. The shallow groove 31 also permits the drilling fluid and foreign matter carried therein to pass upwardly past the roller from the lower casing regions.

I claim:

1. A swedge adapted to be lowered to a point remote from the surface in a casing set in a well including a shank rotatable about the axis of the casing, and a conoidal roller mounted on said shank for rotation about an inclined axis fixed with respect to said shank, said roller closely fitting the interior of the casing and forming the sole support of said roller and shank against transverse movement in the casing.

2. A swedge adapted to be lowered to a point remote from the surface in a casing set in a well including a shank rotatable about the axis of the casing, and a roller mounted on said shank for rotation about an inclined axis fixed with respect to said shank, said roller being of generally conoido-spherical shape tapering in one direction toward its axis from a maximum diameter at right angles to the roller axis, said roller being generally spherical in the opposite direction, the spherical portion of said roller closely fitting the interior of the casing and forming the sole support of said roller and said shank against transverse movement in the casmg.

3. A swedge adapted to be lowered to a point remote from the surface in a casing set in a well including a shank rotatableabout the axi of the casing, and a conoidal roller mounted on said shank for rotation about an inclined axis fixed with respect to said shank, one half of the apex angle of said conoid being greater than the angle of inclination of the axis of said roller. said roller closely fitting the interior of the casing and forming the sole support of said roller and shank against transverse movement in the casing.

4. A swedge adapted to be lowered to a point remote from the surface in a casing set in a well including a shank rotatable about the axis of the casing, and a roller mounted on said shank for rotation about an inclined axis fixed with respect to said shank, said roller being of generally conoido-sphenical shape tapering in one direction toward it axis from a maximum diameter at right angles to the roller axis, one half of the apex angle of said tapered portion being greater than the angle of inclination of the am's of rotation of said roller, said roller being generally spherical in the opposite direction, the spherical portion of said roller closely 5 fitting the interior of the casing and forming the sole support of said roller and shank against transverse movement in the casing.

JOHN A. ZUBLIN.

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